Biological degradation of aflatoxin M 1 by Bacillus pumilus E-1-1-1

Abstract

Aflatoxin M 1 (AFM 1 ) is a potent mycotoxin which causes serious health concerns in developing countries, where it is mainly found in milk, meat, and other foods. Biological detoxification is a promising method for eliminating AFM 1 . The aim of this work was to search for AFM 1 -degrading bacterial strains from animal waste, soil, and activated sludge. High-performance liquid chromatography and Fourier-transform infrared spectroscopy were used to analyze the AFM 1 degradation products. A strain designated E-1-1-1 was obtained from African elephants feces, with the degradation ratio of AFM 1 reaching 89.55% in 12 hr. Based on morphology, physiological and biochemical tests, and 16S rRNA gene sequence analysis, strain E-1-1-1 was identified as Bacillus pumilus. The culture supernatant of B. pumilus E-1-1-1 degraded AFM 1 effectively, whereas the cells and cell extracts of B. pumilus E-1-1-1 were far less effective. Carbon and nitrogen sources had highly significant effects on the degradation of AFM 1 by B. pumilus E-1-1-1. The AFM 1 -degrading strain, B. pumilus E1-1-1, could have great potential in industrial applications.